1. Field of the Invention
The present invention relates to an electronic component module. More specifically, the present invention relates to an electronic component module having a metal case arranged to cover components mounted on a substrate.
2. Description of the Related Art
FIG. 8 is a perspective view showing an example of a conventional electronic component module. An electronic component module 1 includes a substrate 2. The substrate 2 has a plurality of concave portions 3 on the edges thereof. Electrodes (not shown) are formed at these concave portions 3 and are connected to an electrode pattern (not shown) formed on a main surface of the substrate 2. Electronic components are mounted on the electrode pattern formed on the main surface of the substrate 2, thus forming a circuit. Then, a metal case 4 is attached to the substrate 2 so as to cover the mounted electronic components.
The metal case 4 includes a covering portion 5 that covers the mounted electronic components. Leg portions 6 are formed at an angle relative to the sides defining the corners of the covering portion 5. A foot 7 is formed at the tip of each leg portion 6 by bending the leg portion 6. Bonding electrodes 8 are formed at the four corners of the substrate 2, a n d the feet 7 are soldered to the bonding electrodes 8. In addition, a claw 9 formed of a long-claw portion 9a and short-claw portions 9b is formed on the metal case 4, which are used for positioning of the metal case 4. In this case, the relative position of the metal case 4 to the substrate 2 is determined by fitting the long-claw portion 9a to one of the concave portions 3 of the substrate 2. In addition, the distance between the mounting surface of the substrate 2 and the covering portion 5 of the metal case 4 is determined by the short-claw portions 9b in contact with the main surface of the substrate 2 at both sides of the concave portion 3 in which the long-claw portion 9a is fitted (refer to Japanese Unexamined Patent Application Publication No. 2002-57234).
However, demands for reduction in size of such electronic component modules are increasing, and it is required that a main surface of a substrate, which serves as a mounting surface for holding components thereon, be entirely used as a mounting area. Therefore, it is becoming difficult to secure spaces for bonding electrodes to which feet of a metal case are soldered and a space for a concave portion that receives a long-claw portion and permits short-claw portions to come into contact with the main surface of the substrate.